I saw this video last night and thought it to be very interesting.
With the brain stem controlling all vital organ functions i.e. heart rate, blood pressure, respiration, and various other vital organ functions, it appears safe to say you need to get your upper cervical spine checked on a regular basis to ensure zero interference at the brain stem level.
What happens when you have interference there? Look what happened to Christopher Reeve when he shattered his atlas.
Enjoy the video!